title: Studies on the pargyline-binding site of different types of monoamine oxidase.
abstract: [3H]Pargyline has been covalently linked to active sites of both type A and type B monoamine oxidase (MAO) obtained from various tissues. Rat heart and human placenta were chosen to represent predominantly type A MAO, pig and bovine livers to represent type B MAO, and rat liver and brain to represent mixed type A and type B MAO's. The [3H]pargyline-MAO adducts were isolated and hydrolyzed by proteolytic enzymes, and the labelled peptides (pargyline-binding sites) separated and compared by paper chromatography and by paper electrophoresis at various pH values. Only one common pargyline peptide was obtained from all the different MAO's. The alternative A and B sites were assessed after preincubation of rat liver MAO with the selective inhibitors deprenyl (to block the B site) and clorgyline (to block the A site). Following proteolysis of the [3H]pargyline of both type A and type B MAO from this pretreated rat liver, MAO has been purified by a series of chromatographic and electrophoretic procedures. Micro-Edman degradation, followed by dansylation, revealed the amino acid sequence to be Ser-Gly-Gly-Cys(X)-Tyr. It is concluded that the primary structures immediately surrounding the pargyline-binding sites are identical for both type A and type B MAO in these tissues.
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001665:Binding Sites; D002417:Cattle; D003010:Clorgyline / Q000494:pharmacology; D005260:Female; D006801:Humans; D066298:In Vitro Techniques; D008099:Liver / Q000201:enzymology; D008297:Male; D008995:Monoamine Oxidase / Q000378:metabolism*; D010293:Pargyline / Q000378:metabolism*; D010447:Peptide Hydrolases; D011247:Pregnancy; D051381:Rats; D012642:Selegiline / Q000494:pharmacology; D014018:Tissue Distribution
chemical_list: D012642:Selegiline; D010293:Pargyline; D008995:Monoamine Oxidase; D010447:Peptide Hydrolases; D003010:Clorgyline